Jothar. The man from U.N.C.L.E.
Ever hear of spoofing an IP address (it is something Trolls would do)? Ever hear of a static IP address? Not everyone uses DHCP as efficient as it is. One can ask their ISP for a static IP. I have a static IP address from my wireless provider, and can be anywhere in the world with my blackberry, as far as I know, with the same IP address (certainly anywhere in the USA or Canada). The “evidence” you have is flimsy, but if you are comfortable with it, call the local Australian Hatzala and tell them not to answer his or her call on shabbos.